Altus is a city and county seat in Jackson County, Oklahoma, United States. The population was 19,813 at the 2010 census, a loss of 7.7 percent compared to 21,454 at the 2000 census.Altus is home to Altus Air Force Base, the United States Air Force training base for C-17, and KC-135 aircrews. It is also home to Western Oklahoma State College and Southwest Technology Center.